Stitch formation



March 26, 1963 J. M. wAsHBuRN STITCH FORMATION 2 Sheets-Sheet 1 FiledDec. 29, 1958 fnvenor: John/MWLsh/burn #5M His At orne'ys March 26, 1963J. M. wAsHBURN STITCH FORMATION 2 Sheets-Sheet 2 Filed Deo. 29, 1958 Inven/tor: JohnM Washburn,

United States Patent Office 3,082,724 Patented Mar. 26, 1963 3,082,724STITCH FORMATION John M. Washburn, West Hartford, Coun., asslgnor t TheMorrow Machine Company, Hartford, Conn., a corporation of ConnecticutFiled Dec. 29, 1958, Ser. No. 783,397 Claims. (Cl. 112-269) Thisinvention relates to stitch formation, and more particularly to animproved form of three thread overedge stitch particularly .adapted tojoin work material edges either when the plies of material are insuperimposed relation or in a relationship that is established whensuperimposed plies of material with the stitching applied thereto areopened or hinged into a relationship wherein the fabric edges becomewhat is commonly designated an abutted seam.

A primary object of the invention is to provide an overedge stitch forjoining work material, the stitch being effective to maintain plies ofmaterial in abutted relationship even if one of the needle threads isbroken.

Other objects and advantages of the invention will become apparent byreference to the following specification taken in conjunction with theaccompanying drawings.

In the drawings:

FIG. l is a perspective view showing a partially completed seam to whichstitching has been applied in accordance with the invention; and

FIG. 2 is a perspective view showing the stitch of the present inventionwith work pieces abutted.

The stitch 0f the present invention is formed from three continuousthreads: needle threads 1 and 2 and covering thread 3. The threads 1, 2and 3 may be formed into the seam by a two needle Merrow overedge sewingmachine of the type manufactured by the assignee of this application;threads 1 and 2 being placed by the needles of the machine and coveringthread 3 being manipulated by the loopers of the machine. To form a seamjoining work material along an abutted edge, the work material ispositioned, as shown in FIG. l, in two plies M1 and M2 which aresuperimposed upon each other with the edges to be joined in verticalalignment. Needle thread 1 is formed into a series of fabric penetratingloops such as 4, connected in series by runs such 4as 4. Each loop 4extends from its open end or base at a penetration point 5 through thefabric, thence along the under surface of the fabric to a point beyondthe fabric edge and thence upwardly to locate the closed end or bighto-f the loop adjacent the aligned edges ysubstantially in a planecoincident with that of the upper surface of the work material.Penetration points 5 lie along a line which is generally parallel to theedge of the work material, the line of penetrations being spaced fromthe edge of the fabric by a xed distance.

As will more clearly be apparent, the arrangement of threads at thesepoints 5 of fabric penetration serves as an anchorage. A loop of needlethread 1 starts from a point of .anchorage 5 and extends directlythrough the Worn material, `but a loop of needle thread 2, as loop 6,has its open end or base located at a penetration point 5 and passesfrom there along the upper surface of the work material to a fabricpenetration point as 10. These penetration points are laterally alignedwith penetration points 5, since the thread placing needles of the twoneedle overedge machine are parallel to each other, and lie along a lineparallel to the line of penetration points 5 but at a greater distancefrom the edge of the work material. Each loop 6 emerges from a fabricpenetration 10 and continues along the under surface of the fabric to apoint beyond the fabric edge ,and thence upwardly a sufficient distanceto bring the bight of loop 6 into registering paired relationship withthe bight of a loop 4. A straight run of thread 2, as 6', extends nextto run 4 of thread 1 and from one penetration point 5 to another.

A third continuous thread 3, comprising a covering or locking thread, isformed into a series of loops 12 and runs 12. Each loop 12 is loopedthrough the bights of a registering pair of loops 4 and 6 of threads 1and 2 respectively and from this point extends obliquely over the uppersurface of work material to the anchorage or penetration point 5 of thenext succeeding registering pair of loops 4 and 6 where the bight ofloop 12 extends around the bases or ends of adjacent loops 4 and 6 tomaintain runs 6 of needle thread 2 in close relationship with runs 4 ofneedle thread 1.

When the previously superimposed plies of work material M1 and M2 areopened as a hinge into abutted relation as shown in FIG. 2 it is seenthat loops 4 of thread 1 extend on the under side of the materialdirectly from penetration points 5 in material M1 to penetration pointsS in material M2. Runs 4 of thread 1 are on the upper surface of workmaterial M1. Also it is seen that the penetration points 10, 10 forloops 6 of thread 2 are, in respect to each ply of work material M1 andM2, laterally offset outside the alignment of penetration points 5, 5respectively for loops 4 of thread 1. Loops 12 of thread 3 with theirbights anchored .at penetration points 5, extend on the upper surface ofboth plies of work material and thence through registering bights ofloops 4 and 6 included in a preceding unit of stitch formation. Inasmuchas the bight of loop 6 is anchored in its registering relationship witha bight of a respective loop 4 the position of penetration 10' in workmaterial M2 becomes offset from the line of runs 12 of loops 12. Thisoffset of penetration points 10 in material M2 is permitted by excessthread provided when the loops 6 are extended through the fabric plieswhen they are iu superimposed relation.

Because of the above described relationship, if either needle thread 1or Z is broken, the other thread will hold the seam with the edges ofplies M1 and M2 maintained in abutment.

The foregoing description is to be considered exemplary rather thanlimiting and the true scope of the invention is that defined by thefollowing claims.

I claim:

1. An overedge chain stitch seam comprising a pair` of continuous needlethreads for-med into two series of loops penetrating a piece of fabricat different distances from one edge of the fabric and having portionsextending beyond said edge, and a covering thread formed into acorresponding series of loops interlooped with the loops of said needlethreads yby extending through said portions of the loops of both needlethreads and about adjacent loops of both needle threads at the pointswhere the series of loops of that one of said needle threads closest tosaid edge penetrate the fabric.

2. An overedge chain stitch seam comprising a first continuous needlethread formed into a rst series of loops penetrating a piece of fabricat spaced points lying along a rst line spaced inwardly from an edge ofsaid fabric, a second continuous needle thread formed into a secondseries of loops passing through said fabric at spaced points lying alonga second line located between said edge and said first line, both ofsaid series of loops having bight portion-s projecting from one surfaceof said fabric, the bight portions of each loop of said rst series beinglocated adjacent the bight portions of a loop of said second series, anda continuous covering thread formed into a third series of loops, eachloop of said third series being looped through adjacent bight portionsof loops of said iirst and said second series and having bight portionslooped around adjacent loops of said first and said second series on theopposed surface of said fabric at points of fabric penetration lying onsaid second line.

3. An overedge chain stitch seam comprising a first continuous needlethread formed into a rst series of fabric penetrating loops connected byruns of said first thread lying on one surface of a piece of fabric ingenerally parallel spaced relationship with an edge of said fabric, eachloop of said first series extending from between adjacent runs of saidfirst thread away from said edge and through said fabric at apenetration point and having a bight portion projecting from theopposite surface of said fabric at said penetration point and beyondsaid edge, a second continuous needle thread formed into a second seriesof fabric penetrating loops connected by run-s of said second threadlying on said one surface of said piece of fabric contiguous to andsubstantially co-extensive with said runs of said lirst thread, eachloop of said second series passing through said fabric at a penetrationpoint located between adjacent runs of said rst thread and having abight portion projecting yfrom said opposite surface of said fabricbeyond said edge into adjacent relationship with the bight portion ofthe adjacent loop of said first series, and a continuous covering threadformed into a third series of loops, each loop of said third seriesextending through the bight portions of adjacent loops of said first andsaid second series and across said one surface of said fabric beneathnext adjacent runs and around the loops of said `first and said secondseries connected between next adjacent runs.

4. An overedge seam for-med `from two continuous needle threads and acontinuous covering thread, said threads being interlooped With eachother in regular succession adjacent one edge of a piece of fabric, eachof said needle threads being `formed into a series of loops with theloops of one series extending through the fabric at points ofpenetration spaced further from Vthe fabric edge than points ofpenetration where the loops of the other series extend through thefabric, said covering thread comprising a series of loops with each looplooped through adjacent loops respectively of the two needle threads ata point adjacent the fabric edge, each loop of said covering threadhaving a bight portion looped about adjacent loops respectively of thetwo needle threads at a point in the line of needle penetrations nearerthe fabric edge.

5. An overedge seam for joining portions of work material along a lineWhere two sections of material are in abutted relaitonship, the seambeing formed from two continuous needle threads and a continuouscovering thread, said .threads being interlooped with each other inregular succession adjacent the abutment line, each of the needlethreads being formed into a series of loops with each loop of one seriesextending through the fabric on opposite sides of the line of abutmentat respective points of needle penetration spaced respectively furtherfrom the line of abutment than corresponding points of needlepenetration of the other series of loops, said covering threadcomprising a series of loops with each loop looped through adjacentloops respectively of the two needle threads at a point on one side ofthe line of abutment and having a lbight portion looped about adjacentloops respectively of the two needle threads at a point in the line ofneedle penetrations nearer the line of abutment.

References Cited in the tile of this patent UNITED STATES PATENTS811,789 Onderdonk Feb. 6, 1906 875,594 Onderdonk Dec. 3l, 1907 2,787,233Walling Apr. 2, 1957 2,903,872 Ledwell Sept. 15, 1959 2,980,917 SlaneApr. 25, 1961 OTHER REFERENCES Federal Standard Stock Catalogue, SectionlV, Part 5, March 4, 1930.

1. AN OVEREDGE CHAIN STITCH SEAM COMPRISING A PAIR OF CONTINUOUS NEEDLE THREADS FORMED INTO TWO SERIES OF LOOPS PENETRATING A PIECE OF FABRIC AT DIFFERENT DISTANCES FROM ONE EDGE OF THE FABRIC AND HAVING PORTIONS EXTENDING BEYOND SAID EDGE, AND A COVERING THREAD FORMED INTO A CORRESPONDING SERIES OF LOOPS INTERLOOPED WITH THE LOOPS OF SAID NEEDLE THREADS BY EXTENDING THROUGH SAID PORTIONS OF THE 